/***************************************************************************

    hashing.h

    Hashing helper classes.

****************************************************************************

    Copyright Aaron Giles
    All rights reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:

        * Redistributions of source code must retain the above copyright
          notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above copyright
          notice, this list of conditions and the following disclaimer in
          the documentation and/or other materials provided with the
          distribution.
        * Neither the name 'MAME' nor the names of its contributors may be
          used to endorse or promote products derived from this software
          without specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY AARON GILES ''AS IS'' AND ANY EXPRESS OR
    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
    WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
    DISCLAIMED. IN NO EVENT SHALL AARON GILES BE LIABLE FOR ANY DIRECT,
    INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
    (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
    SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
    STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
    IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    POSSIBILITY OF SUCH DAMAGE.

***************************************************************************/

#pragma once

#ifndef __HASHING_H__
#define __HASHING_H__

#include "astring.h"
#include "md5.h"
#include "sha1.h"


//**************************************************************************
//  TYPE DEFINITIONS
//**************************************************************************


// ======================> SHA-1

// final digest
struct sha1_t
{
	bool operator==(const sha1_t &rhs) const { return memcmp(m_raw, rhs.m_raw, sizeof(m_raw)) == 0; }
	bool operator!=(const sha1_t &rhs) const { return memcmp(m_raw, rhs.m_raw, sizeof(m_raw)) != 0; }
	operator UINT8 *() { return m_raw; }
	bool from_string(const char *string, int length = -1);
	const char *as_string(astring &buffer) const;
	UINT8 m_raw[20];
	static const sha1_t null;
};

// creation helper
class sha1_creator
{
public:
	// construction/destruction
	sha1_creator() { reset(); }

	// reset
	void reset() { sha1_init(&m_context); }

	// append data
	void append(const void *data, UINT32 length) { sha1_update(&m_context, length, reinterpret_cast<const UINT8 *>(data)); }

	// finalize and compute the final digest
	sha1_t finish()
	{
		sha1_t result;
		sha1_final(&m_context);
		sha1_digest(&m_context, sizeof(result.m_raw), result.m_raw);
		return result;
	}

	// static wrapper to just get the digest from a block
	static sha1_t simple(const void *data, UINT32 length)
	{
		sha1_creator creator;
		creator.append(data, length);
		return creator.finish();
	}

protected:
	// internal state
	struct sha1_ctx 	m_context;		// internal context
};



// ======================> MD5

// final digest
struct md5_t
{
	bool operator==(const md5_t &rhs) const { return memcmp(m_raw, rhs.m_raw, sizeof(m_raw)) == 0; }
	bool operator!=(const md5_t &rhs) const { return memcmp(m_raw, rhs.m_raw, sizeof(m_raw)) != 0; }
	operator UINT8 *() { return m_raw; }
	bool from_string(const char *string, int length = -1);
	const char *as_string(astring &buffer) const;
	UINT8 m_raw[16];
	static const md5_t null;
};

// creation helper
class md5_creator
{
public:
	// construction/destruction
	md5_creator() { reset(); }

	// reset
	void reset() { MD5Init(&m_context); }

	// append data
	void append(const void *data, UINT32 length) { MD5Update(&m_context, reinterpret_cast<const unsigned char *>(data), length); }

	// finalize and compute the final digest
	md5_t finish()
	{
		md5_t result;
		MD5Final(result.m_raw, &m_context);
		return result;
	}

	// static wrapper to just get the digest from a block
	static md5_t simple(const void *data, UINT32 length)
	{
		md5_creator creator;
		creator.append(data, length);
		return creator.finish();
	}

protected:
	// internal state
	struct MD5Context	m_context;		// internal context
};



// ======================> CRC-32

// final digest
struct crc32_t
{
	bool operator==(const crc32_t &rhs) const { return m_raw == rhs.m_raw; }
	bool operator!=(const crc32_t &rhs) const { return m_raw != rhs.m_raw; }
	crc32_t &operator=(const UINT32 crc) { m_raw = crc; return *this; }
	operator UINT32() const { return m_raw; }
	bool from_string(const char *string, int length = -1);
	const char *as_string(astring &buffer) const;
	UINT32 m_raw;
	static const crc32_t null;
};

// creation helper
class crc32_creator
{
public:
	// construction/destruction
	crc32_creator() { reset(); }

	// reset
	void reset() { m_accum.m_raw = 0; }

	// append data
	void append(const void *data, UINT32 length);

	// finalize and compute the final digest
	crc32_t finish() { return m_accum; }

	// static wrapper to just get the digest from a block
	static crc32_t simple(const void *data, UINT32 length)
	{
		crc32_creator creator;
		creator.append(data, length);
		return creator.finish();
	}

protected:
	// internal state
	crc32_t 			m_accum;		// internal accumulator
};



// ======================> CRC-16

// final digest
struct crc16_t
{
	bool operator==(const crc16_t &rhs) const { return m_raw == rhs.m_raw; }
	bool operator!=(const crc16_t &rhs) const { return m_raw != rhs.m_raw; }
	crc16_t &operator=(const UINT16 crc) { m_raw = crc; return *this; }
	operator UINT16() const { return m_raw; }
	bool from_string(const char *string, int length = -1);
	const char *as_string(astring &buffer) const;
	UINT16 m_raw;
	static const crc16_t null;
};

// creation helper
class crc16_creator
{
public:
	// construction/destruction
	crc16_creator() { reset(); }

	// reset
	void reset() { m_accum.m_raw = 0xffff; }

	// append data
	void append(const void *data, UINT32 length);

	// finalize and compute the final digest
	crc16_t finish() { return m_accum; }

	// static wrapper to just get the digest from a block
	static crc16_t simple(const void *data, UINT32 length)
	{
		crc16_creator creator;
		creator.append(data, length);
		return creator.finish();
	}

protected:
	// internal state
	crc16_t 			m_accum;		// internal accumulator
};


#endif // __HASHING_H__
